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When to Plant Scallions in Garfield County, WA

Garfield County, Washington Zone 7a May

This month in Garfield County, Washington

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 9
Avg. first frost September 30
Soil temp (4") 56°F
Watering Critical
Pest pressure Low
Daylight 14.8 hrs
  1. Move scallions into the garden

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

Looking ahead to June
  • Starting indoors: scallions

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Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.

Garfield County, Washington is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.

At an elevation of 3,226 feet, Garfield County receives approximately 17.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Scallions during the growing season. With low rainfall, drip irrigation is essential for growing Scallions successfully. Mulch heavily to conserve soil moisture.

Garfield County, WA (Zone 7a) Short season
144 days
Last Spring Frost May 9
144 growing days
First Fall Frost September 30
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Garfield County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jun 23 – Jul 21
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jul 4 – Aug 1
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Aug 1 – Aug 29

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Garfield County

How your county's soil matches Scallions's growing requirements.

Soil pH

Your soil pH (5.6–6.8) overlaps with Scallions's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Garfield County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Scallions.

Organic Matter

Organic matter is excellent (4.3%) — Scallions will thrive.

How to Plant Scallions

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Scallions

3
successive plantings in your 144-day season

Sow every 5.7 weeks. Last sowing by Jul 22 to harvest before frost.

For a dedicated fall crop, sow by Jul 22.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,214 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Scallions

Scallions needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Scallions Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.1" 0" ❄️ Dormant
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 3" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Garfield County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Scallions Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Scallions needs ~960 GDD — county provides 2,304 GDD Excellent fit

Scallions Planting Timeline — Garfield County, WA

Scallions Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 9 May 9 – May 23
Direct Sow April 25 Apr 25 – May 16
Harvest July 4 Jul 4 – Aug 1
Fall Sowing July 22 Jul 22 – Aug 5

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Fall Sowing Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

144 days in Garfield County

Growing Tips for Scallions in Garfield County

Direct sow Scallions outdoors after May 09 in Garfield County when soil has warmed and frost danger has passed.

Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

Garfield County receives only 18" of rain annually. Scallions needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Scallions in Garfield County, WA?

Garfield County is in Zone 7a with an average last frost of May 9. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Garfield County, WA?

Garfield County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is September 30.

🌱

Your Garfield County Garden Planner — Free

A 24-page printable planner built for Garfield County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Garfield County, WA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.